1. Field of the Invention
The present invention relates generally to integrated circuits, and more particularly to integrated circuit fabrication processes and structures.
2. Description of the Background Art
In an integrated circuit, a “via” is employed to electrically couple a top metal layer to a bottom metal layer. Generally speaking, a via is a hole formed in a dielectric layer separating the top and bottom metal layers. To carry electrical signals from one metal layer to another, a via is filled with an electrically conductive material, such as aluminum or tungsten. As can be appreciated, a via needs to be structurally robust to reliably carry electrical signals. A defect in a via, such as a void, may lead to intermittent problems and, depending on the severity of the defect, may result in full circuit failure.